1- In an oven proof saucepan or casserole, heat the oil and add the onions, cook over a low heat for 15 minutes until golden.
2- Add the garlic and the sugar.
3- Heat the beefstock ab=nd add to the onions, mix well.
4- Bring to the boil, then turn the heat right down and simmer for 20-30 minutes. Season to taste.
5- Lightly grill (or toast) the slices of baguette, top with cheese.
6- Float the cheese topped baguette on the soup, and place under the grill for 5 minutes, so that the cheese melts.
7- Sprinkle parsley on top and serve.